Diffractive electron imaging of nanoparticles on a substrate

• Published in: Nature materials Vol. 4; no. 12; pp. 912 - 916
• Main Authors: Wu, Jinsong, Weierstall, U, Spence, John C. H
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.12.2005
• Subjects: Algorithms; Aperture; Carbon; Carbon - chemistry; Electron microscopes; Electrons; Gold - chemistry; Image Processing, Computer-Assisted; Materials science; Microscopy; Microscopy, Electron, Transmission; Nanoparticles; Nanostructures - analysis; Nanostructures - chemistry; Nanotechnology; Radiation; Substrate Specificity; X-Ray Diffraction; United States > US; Arizona
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat1531

The observation of the detailed atomic arrangement within nanostructures has previously required the use of an electron microscope for imaging. The development of diffractive (lensless) imaging in X-ray science and electron microscopy using ab initio phase retrieval provides a promising tool for nanostructural characterization. We show that it is possible experimentally to reconstruct the atomic-resolution complex image (exit-face wavefunction) of a small particle lying on a thin carbon substrate from its electron microdiffraction pattern alone. We use a modified iterative charge-flipping algorithm and an estimate of the complex substrate image is subtracted at each iteration. The diffraction pattern is recorded using a parallel beam with a diameter of approximately 50 nm, illuminating a gold nanoparticle of approximately 13.6 nm diameter. Prior knowledge of the boundary of the object is not required. The method has the advantage that the reconstructed exit-face wavefunction is free of the aberrations of the objective lens normally used in the microscope, whereas resolution is limited only by thermal vibration and noise.